/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.sorter;



import com.bff.gaia.unified.sdk.values.KV;



import java.io.IOException;



/**

 * Interface for classes which can sort {@code <key, value>} pairs by the key.

 *

 * <p>Records must first be added by calling {@link #add(KV)}. Then {@link #sort()} can be called at

 * most once.

 *

 * <p>TODO: Support custom comparison functions.

 */

interface Sorter {



  /**

   * Adds a given record to the sorter.

   *

   * <p>Records can only be added before calling {@link #sort()}.

   */

  void add(KV<byte[], byte[]> record) throws IOException;



  /**

   * Sorts the added elements and returns an {@link Iterable} over the sorted elements.

   *

   * <p>Can be called at most once.

   */

  Iterable<KV<byte[], byte[]>> sort() throws IOException;

}